From 95644099f59087e6c83c7d04747a180ce8955772 Mon Sep 17 00:00:00 2001 From: Curtis McEnroe Date: Sat, 17 Dec 2016 00:18:36 -0500 Subject: Day 14 --- src/bin/day14.rs | 60 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 60 insertions(+) create mode 100644 src/bin/day14.rs (limited to 'src/bin') diff --git a/src/bin/day14.rs b/src/bin/day14.rs new file mode 100644 index 0000000..b22e88d --- /dev/null +++ b/src/bin/day14.rs @@ -0,0 +1,60 @@ +extern crate crypto; + +use std::collections::VecDeque; +use std::io::{self, Read}; +use std::iter; + +use crypto::digest::Digest; +use crypto::md5::Md5; + +fn md5(salt: &str, index: u32) -> String { + let mut md5 = Md5::new(); + md5.input_str(salt); + md5.input_str(&index.to_string()); + md5.result_str() +} + +fn solve(salt: &str) -> u32 { + let mut hashes = VecDeque::new(); + for i in 0..1001 { + hashes.push_back(md5(salt, i)); + } + + let mut keys = 0; + let mut index = 0; + while let Some(hash) = hashes.pop_front() { + let triple = hash.as_bytes() + .windows(3) + .filter(|w| w[0] == w[1] && w[1] == w[2]) + .map(|w| w[0]) + .next(); + + if let Some(ch) = triple { + let quintuple: String = iter::repeat(ch as char).take(5).collect(); + if hashes.iter().any(|hash| hash.contains(&quintuple)) { + keys += 1; + if keys == 64 { + return index; + } + } + } + + index += 1; + hashes.push_back(md5(salt, 1000 + index)); + } + + unreachable!() +} + +fn main() { + let mut input = String::new(); + io::stdin().read_to_string(&mut input).unwrap(); + + println!("Part 1: {}", solve(input.trim())); +} + +#[test] +#[ignore] +fn part1() { + assert_eq!(22728, solve("abc")); +} -- cgit 1.4.1 ='author'>author
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2021-01-31Add The Rosewater RedemptionJune McEnroe
Remembering how to read 2021.
2021-01-29Use int when checking for EOFJune McEnroe
2021-01-28Move gpl.c and agpl.c templates out of etcJune McEnroe
2021-01-27Set para and sect for mdocJune McEnroe
Copied from the OpenBSD defaults.
2021-01-26Use First state to match keyword at beginning of lineJune McEnroe
Otherwise keywords at the beginnings of lines with preceeding whitespace are not matched.
2021-01-25Install vi on Linux and nvi on macOSJune McEnroe
2021-01-25Use vi and lessJune McEnroe
I haven't used neovim in a couple weeks by now, so I may as well commit this.
2021-01-20Use mtags for sh in source-filterJune McEnroe
2021-01-20Generate tags for sh files in mtagsJune McEnroe
Only matches functions declared at the beginnings of lines, but I'm fine with that.
2021-01-20Add messy sh lexerJune McEnroe
Surprisingly seems to work for everything I looked at in my repos.
2021-01-20Add all target to git.causal.agency MakefileJune McEnroe
2021-01-20Remove Lua supportJune McEnroe
Lua support is unused and the dlsym fwrite/write hacks horrify me. Clean it up.
2021-01-20Fix tests for diff spansJune McEnroe
2021-01-20Avoid matching ':' in make tagsJune McEnroe
Otherwise a :: rule includes one of the ':'s in the tag name.
2021-01-19Prefer tag matches not preceded by [[:alnum:]]June McEnroe
Otherwise the "id" in "void" matches for "void id".
2021-01-19Escape \ and / in mtags search patternsJune McEnroe
2021-01-20Use mtags in source-filterJune McEnroe
2021-01-19Add mtags to generate tags for make and mdocJune McEnroe
2021-01-19Map tags to IDs using only [[:alnum:]-._]June McEnroe
2021-01-19Don't use a pager if reading standard inputJune McEnroe
2021-01-19Support BSD make syntax and match *.amJune McEnroe
These don't really go together, but...
2021-01-19Match tab following escaped newline in make assignmentsJune McEnroe
Otherwise it ends up going into Shell state.
2021-01-18Allow matching lexers using first input lineJune McEnroe